Hello,
LCD display interface supports only one resolution and this is the native resolution of the LCD display.
Refer the LCD displays datasheet a special timing have to be held.
The display in this starterskit (EDT ET070080DH6) uses a native resolution of 800x480. When I change the resolution in WinCE7, the entire OS seems to hang (only recoverable by resetting the device). Does this mean that the 800x480 resolution is the only resolution that this display supports ? Or is it an issue with this version of the OS ?
Some more information on this topic. An LCD display can always only show its native resolution. It has an interface that accepts the RGB data of the pixels along with the pixel clock. One clock per available pixel. If you change for example the x-resolution to a lower value, the remainnig pixels in each row remain blank or even the pixels of the next row will show up in this space. If you increase the x-resolution to a higher value, you will only see the first pixels that fit onto the existing row.
So this is not a restriction of our implementation, it is generally the same with all hardwares.
What you see on a PC monitor is something different. These monitors have additional hardware that can scale the image, so that either pixels are duplicated in a row (for upscaling) or pixels are dropped (for downscaling). But the final data stream that arrives at the LCD panel of the monitor is again the exact native resolution of the display. So the display itself is again as "dumb" as in our case.
So if you want to use different resolutions with one display on the efusA9, you have to put such an additional scaling hardware in the path between board and display like in the PC monitor.
You can also use a software solution. For example you can draw your image content to an off-line buffer of any size you want. And then periodically call a bitblt function to scale the content of this buffer to the native display size and copy it to the real framebuffer. In fact such a bitblt function would again use a hardware scaler of the Freescale CPU, so it would be a hardware accelerated software solution.
Your F&S Support Team
